This invention relates generally to the field of electronic circuits and more specifically to the use of distributed broadband technology for interference isolation enhancement.
Electrical circuits, which are in close physical proximity and which must share common supply, ground, and substrate connections, can cause the associated electrical signals of those circuits to become difficult to isolate. The difficulty in signal isolation is caused by electromagnetic interference (EMI). EMI is often caused by high frequency components that radiate electromagnetic energy (the system clock is an example). EMI is also affected by the propagation mode of electrical signals within a circuit. Differential mode signals, in which two signals carry current in opposite directions, are less susceptible to EMI than common mode signals. Common mode signals cause more significant EMI issues because the signal current flows in one direction, and the conductors in the signal path can generate unwanted capacitances or inductances that degrade the signal quality in the primary signal path as well as nearby signal paths.
Common EMI mitigation strategies include reducing the power level of potential noise sources as much as possible, minimizing the amount of coupling between signals of interest (SOI) and EMI generating components, and filtering EMI components. Reducing the power level is a nice solution but is not practical in many design situations, and filtering xe2x80x98noisyxe2x80x99 components complicates the design process and increases overall component cost.
There are several design approaches that may be used to mitigate the effects of signal distortion due to coupling from the noise contributions of other components in the integrated circuit. Some commonly applied mitigation techniques include grounding, shielding, and guard ring isolation. Grounding, filtering and shielding are commonly used techniques that can significantly reduce spurious emissions, and improve signal isolation. However, filtering, guard ring isolation, and shielding all require additional electronics components, complicate the design process, and increase the production cost of IC electronics.
Another commonly used technique in the design of small integrated circuit electronics is the use of common circuit partitioning. Since the circuits in close proximity tend to interfere with each other at frequencies of interest, physical separation of interfering circuits is used to reduce these noise effects. These undesired noise contributions can become a system complexity factor used to determine the partitioning of common circuits on a single integrated component. For example, direct current (DC)-to-DC converters are considered noise interference generators that should not be integrated with radio frequency (RF) power amplifier circuits on a common component. However, DC-to-DC converters are an important solution for the issue of battery life efficiency enhancement and this partitioning constraint has unfortunate design implications.
In light of the foregoing, there is an unmet need in the art for a method and structure that provides enhanced signal isolation capabilities while allowing DC signal circuitry to be integrated with RF power amplification circuits. There is a further need in the art for an integrated circuit design technique that allows noise interference generators to be placed in close proximity to RF amplification components, thereby reducing potential crosstalk with other integrated circuit components.